Nitrous oxide emission, global warming potential, and denitrifier abundances as affected by long-term fertilization on Mollisols of Northeastern China

ABSTRACT

A long-term field experiment was performed to assess the effects of fertilization regimes on greenhouse gas emissions, soil properties, soil denitrifies, and maize (Zea mays) grain yield on Mollisols of Northeastern China. Chemical nitrogen (N), phosphorus (P), and potassium (K) fertilizers plus pig manure (MNPK) treatment significantly increased soil N₂O emissions by 29.9–226.4% and global warming potential (GWP) by 29.8–230.7% compared to unfertilized control (CK), chemical N fertilizer only (N), chemical N, P, and K fertilizers (NPK) and chemical N, P, and K fertilizers plus corn straw (SNPK) treatments. However, the MNPK treatment yielded similar greenhouse gas intensity (GHGI) as compared with other treatments, mainly due to higher maize grain yield. There were also higher gene copy numbers of nirK, nirS, and nosZ in topsoil (0–20 cm depth) under MNPK treatment. Automatic linear modeling analysis indicated that main factors influencing soil N₂O emissions were soil organic carbon (SOC), NO₃⁻ content, and nirK gene abundance. Although the application of chemical fertilizers plus organic manure increases N₂O emissions due to higher N and C availability and nirK gene activity in the soil, this is still a promising fertilizer management due to its notable enhancement of maize grain yield and SOC content.

KEYWORDS:

• Greenhouse gas emissions
• climate change
• organic manure
• soil physicochemical properties
• denitrification potential

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Chinese National Basic Research Program [2015CB150404]; National Natural Science Foundation of China [31671642]; Special Fund for Agro-scientific Research in the Public Interest [20153120]; Chinese National Key Researchand Development Program [2016YFE0112700-3]; Innovation Project of Chinese Academy of Agricultural Sciences [CAAS-XTCX2016008]; China Scholarship Council.